# CVE-2023-28427: Prototype pollution in matrix-js-sdk


- **Severity:** High 8.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 28 Mar 2023
- **Updated:** 18 Feb 2025
- **Also known as:** CLEANSTART-2024-KH83435, DEBIAN-CVE-2023-28427, GHSA-mwq8-fjpf-c2gr, MGASA-2023-0132, UBUNTU-CVE-2023-28427, openSUSE-SU-2024:12823-1

## What is CVE-2023-28427?

CVE-2023-28427 is a high-severity vulnerability in matrix-org matrix-js-sdk, published on 28 Mar 2023. 

### Official description

matrix-js-sdk is a Matrix messaging protocol Client-Server SDK for JavaScript. In versions prior to 24.0.0 events sent with special strings in key places can temporarily disrupt or impede the matrix-js-sdk from functioning properly, potentially impacting the consumer's ability to process data safely. Note that the matrix-js-sdk can appear to be operating normally but be excluding or corrupting runtime data presented to the consumer. This vulnerability is distinct from GHSA-rfv9-x7hh-xc32 which covers a similar issue. The issue has been patched in matrix-js-sdk 24.0.0 and users are advised to upgrade. There are no known workarounds for this vulnerability.

Weakness: CWE-1321 (Improperly Controlled Modification of Object Prototype Attributes)

## Which versions are affected by CVE-2023-28427?

2 open source packages ship an affected version, including matrix-js-sdk. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `matrix-js-sdk` | npm | All versions | 24.0.0 |
| `matrix-js-sdk` | npm | All versions | 24.0.0 |
| `element-web` | openSUSE:Tumbleweed | All versions | 1.11.26-1.1 |

Products: Matrix Javascript Sdk.

## How do I fix CVE-2023-28427?

Upgrade matrix-js-sdk to 24.0.0 or later.

## Is CVE-2023-28427 being exploited?

There is no known exploitation of CVE-2023-28427 in the wild and no public exploit code.

## Other vulnerabilities in matrix-org matrix-js-sdk

- [CVE-2022-39250](https://insights.sbomify.com/CVE-2022-39250/): Matrix JavaScript SDK vulnerable to key/device identifier confusion in SAS verification (high 8.6)
- [CVE-2022-39251](https://insights.sbomify.com/CVE-2022-39251/): Matrix Javascript SDK vulnerable to Olm/Megolm protocol confusion (high 8.6)
- [CVE-2022-36059](https://insights.sbomify.com/CVE-2022-36059/): Prototype pollution in matrix-js-sdk (high 8.2)
- [CVE-2022-39249](https://insights.sbomify.com/CVE-2022-39249/): Matrix Javascript SDK vulnerable to impersonation via forwarded Megolm sessions (high 7.5)
- [CVE-2021-40823](https://insights.sbomify.com/CVE-2021-40823/): matrix-js-sdk can be tricked into disclosing E2EE room keys to a participating homeserver (medium 5.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-28427 and fix it if it is affected.

What it is: CVE-2023-28427 is a high-severity vulnerability in matrix-org matrix-js-sdk, published on 28 Mar 2023. 
Exploitation: There is no known exploitation of CVE-2023-28427 in the wild and no public exploit code.

Affected packages and fixed versions:
- matrix-js-sdk (npm): affected all versions; fixed in 24.0.0
- matrix-js-sdk (npm): affected all versions; fixed in 24.0.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2023-28427/ (Markdown: https://insights.sbomify.com/CVE-2023-28427/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-28427
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-28427
- OSV: https://osv.dev/vulnerability/CVE-2023-28427

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-28427/
Summaries are generated and may contain mistakes; the official description above is the record.